Expandable trochar, especially for medical purposes

ABSTRACT

An expandable tubular element, especially for use as a trochar, in which one or more thin metal strips, such as stainless steel, are arranged to form a tubular element with the tubular element being radially expandable and contractible.

United States Patent 1191 Kim et a1.

[451 Feb. 5, 1974 EXPANDABLE TROCHAR, ESPECIALLY FOR MEDICAL PURPOSES[76] Inventors: Sung Soo Kim, 4724 Imperial Park Dr., Fort Wayne, Ind.46815; Andress Dusseau, R.R. No. 1, Geneva, 1nd. 46740 [22] Filed: June12, 1972 21 Appl, No.: 261,794

[52] US. Cl. 128/347, 128/343 [51] Int. Cl A61b 17/34 [58] Field ofSearch 128/347 351, 341,

[56] References Cited UNITED STATES PATENTS 3,044,461 7/1962 Murdock128/4 3,509,883 5/1970 Dibelius 128/348 2,812,758 11/1957 Blumenschein128/20 447,761 3/1891 Clough 128/17 FOREIGN PATENTS OR APPLICATIONS330,629 6/1930 Great Britain 128/3 Primary ExaminerDalton L. TruluckAttorney, Agent, or Firm-Albert L. Jeffers; Roger M. Rickert [5 7]ABSTRACT An expandable tubular element, especially for use as a trochar,in which one or more thin metal strips, such as stainless steel, arearranged to form a tubular element with the tubular element beingradially expandable and contractible.

17 Claims, 12 Drawing Figures PATENTED FEB 5 I974 SHEET 1 BF 4EXPANDABLE TROCIIAR, ESPECIALLY FOR MEDICAL PURPOSES The presentinvention relates to an expandable and contractible tubular element,especially for medical purposes and is referred to herein as a trochar.

Trochars are employed in medical and surgical practice for gainingaccess to interior regions of the body for the purpose of draining fluidtherefrom, for the placement of treatment materials therein, or for theplacement of catheters. Also, trochars are employed for examinationpurposes in connection with the placement of such instruments as aperitoneoscope or a thorascoscope. Trochars can be employed assuprapubic devices to drain distended bladders, or to place catheterstherein.

Trochars are also employed in connection with the evacuation of fluidfrom the abdominal cavity, a procedure referred to as paracentesis, andfor the evacuation of fluid from the plural cavity or the placement of atube into the plural cavity, a procedure referred to as thoracentesis.

Most of the foregoing procedures in which a trochar is employed requirethe forming of an incision, or a puncture, in a certain body area andthe introduction of the trochar into the body through the incision orpuncture.

In any case, a high degree of skill is required to insert the trocharinto the proper position, especially when the trochar is of substantialdiameter. It will be evident, from the foregoing, that some trochars,especially those large enough to accommodate an instrument, such as anoptical viewing instrument, must. be of substantial size and theplacement of such trochars involves a high degree of skill on the partof the operator and involves considerable discomfort to the patient.

With the foregoing in mind, a primary objective of the present inventionis the provision of a trochar which avoids the drawbacks anddifficulties referred to above.

Another object of the present invention is the provision of a trocharwhich requires the minimum amount of skill for placement and involvesthe minimum amount of discomfort to the patient.

A particular object of the present invention is the provision of atrochar which can radially be expanded after placement.

Still another object of the present invention is the provision of atrochar which is radially expansible and which is also reusable.

It is also an object to provide an expandable trochar so constructed asto be able to receive a removable puncturing instrument which will formthe puncture to receive the trochar and which will guide the trocharinto position.

A still further object of the invention is the provision of anexpandable trochar having a curved removable blunt shaped guidingportion which can be used as an urethral dilator or uterine dilator.

BRIEF SUMMARY OF THE INVENTION The expandable trochar according to thepresent invention comprises a tubular element, especially a stainlesssteelelement, which can be expanded in the radial direction.

Trochar has been defined in the dictionary as a sharp object guiding theintroduction of a tube into a bodylike needle. In medicine and in thisapplication the term trochar is used to define in combination a punctureguiding rod cooperating with a tube. Also, the tube can be referred toas a trochar when the puncture guiding rod is removed.

The trochar in its simplest form can be a strip of stainless steel orother suitable material wound up spirally to form the tube with the freeends of the thus wound up tube being movable in the circumferentialdirection to cause expansion and contraction of the trochar.

In another form which the trochar can take, two tubular stainless steelelements which are split in the longitudinal direction are placed incoaxial, coextensive, nesting relation and expansion and contraction ofthe trochar is accomplished by varying the diameter of the inner one ofthe split tubular elements.

In still another form, which the trochar can take, two i or more stripsof stainless steel are folded back on themselves to form U-shapedmembers with about half of the length of each member commencing from theother end whereby, upon forming the members so as to be arcuate whenviewed endwise, the members can be disposed in mutually telescopicengagement.

In this case, the diameter of the trochar is adjusted by adjusting thedegree of telescopic engagement of the members with each other.

In yet another form which the trochar can take, a tubular stainlesssteel element is flattened out and is then formed to an arcuateconfiguration and the ends thereof are inserted between a pair of spacedparallel curved stainless steel strips to form the tubular trochar.

In this case, the diameter of the trochar is adjusted by adjusting thedegree of telescopic engagement of the ends of the first mentioned sheetwith the last two mentioned parallel sheets.

In every case, the trochar is tubular so that it can receive a removablepiercing instrument. The trochar at the end opposite the end which isintroduced into the body, has a guide ring which supports the elementsof the trochar and permits manipulation thereof and the securing thereofto the body.

The foregoing objects as well as still other objects and advantages ofthe present invention will become more apparent upon reference to thefollowing detailed specification taken in connection with theaccompanying drawings in which:

FIG. 1 is a side elevational view of a trochar according to the presentinvention in radially collapsed position and with a puncture devicemounted therein.

FIG. 2 is a side elevational view similar to FIG. 1 but showing thetrochar in maximum expanded position.

FIG. 3 is a plan sectional view indicated by line III- III on FIG. 1.

FIG. 4 is a view like FIG. 3, but shows the trochar in maximum expandedcondition. I

FIG. 5 is a fragmentary sectional view indicated by line V-V on FIG. 1,showing a guide member forming a part of the trochar.

FIG. 6 is a fragmentary plan view drawn at enlarged scale and-showingtab elements which limit the expand-' ability of the trochar.

FIG. 7 is a plan sectional view, showing a modified form which a trocharaccording to the present invention can take.

FIG. 8 is a plan sectional view, showing a further modification.

FIG. 9 is a plan sectional view, showing a still further modification. V

FIG. 10 is a plan sectional view of still another modification.

FIG. 11 is a fragmentary sectional view showing a device for locking thetrochar in adjusted positions of expansion thereof.

FIG. 12 is a fragmentary view showing a modified form of the guidingportion for the trochar when used as a dilator.

DETAILED DESCRIPTION OF THE INVENTION Referring to the drawings somewhatmore in detail, the trocharof FIGS. 1 through 6 will be seen to comprisea rather elongated tubular portion indicated at 10 which is contractibleto its FIGS. 1 and 3 positions and expansible to its FIGS. 2 and 4positions.

The trochar when in its FIG. 1 position is hollow from end to end andcan receive a removable piercing instrument 12 with a piercing point, orneedle, 14. The end of the tubular portion of the trochar which isadjacent point 14, may be beveled or tapered as at 15 to facilitateintroduction of the trochar into a puncture made by point 14.

The end of the trochar opposite point 14, namely, the outer end of thetrochar, is provided with a guide ring 16 which is flanged at 18 asshown in FIGS. 1 and 2. Guide ring 16 is provided with slot means 20 inwhich is slidable rod means or post means or finger piece means 22extending in the radial direction of the trochar.

Reference to FIG. 3, will show more in detail the various elements ofthe trochar. The tubular portion 10 of the trochar is formed of twoelements 24, each of which is a stainless steel strip or other suitablematerial folded back on itself so as to have a closed end at 26 and anopen end at 28. Commencing at the closed end, about half the length ofeach element is formed to a smaller radial dimension, while theremainder of each element is formed to a larger radial dimension. Eachelement is formed concentrically about the longitudinal axis 30 of thetrochar and the smaller end of each element telescopically engages thelarger end of the other element. The elements are formed of thincorrosive resistant metal, such as stainless steel, and are thusflexible.

Attached to the larger end of each of the elements on the radially outerside is a post 32 extending radially outwardly through a pertainingaperture 34 in guide ring 16.

Also attached to each element near the closed end thereof and on theradial outer side is the rod or post, or finger piece, 22 extendingradially outwardly through the circumferential slot 20 in guide ring 16and also through a circumferential slot 40 in the radially outer side ofthe larger end of the other element. By manipulating finger pieces 22along their slots 20, the degree of telescopic engagement of theelements with each other can be adjusted and this will adjust thediameter of the trochar. The finger pieces 22 are threaded at 21 and alock nut 23 serves to lock the trochar in adjusted position.

FIG. 3 shows the trochar in maximum collapsed, minimum diameter,position and FIG. 4 shows the trochar in maximum expanded, maximumdiameter, position and also shows the manner in which finger pieces 22are adjusted in guide ring 16 to accomplish the expansion andcontraction of the trochar.

It is advantageous for the closed end of each element to have connectedthereto an angle piece, or side bar, 42 as shown in FIG. 5 extendingoutwardly through the adjacent slot 40 in the other element and thendownwardly along the outside of the other element, thereby retaining theouter part of each of the said elements in close engagement with theinner part of the other element which is telescopically engagedtherewith.

FIG. 6 will show that the free ends of the longer end of each elementare advantageously provided with turned in edges, or tabs, 44 whichcooperate with turned out tabs 46 near the closed ends of the otherelements, thereby to limit the expanding movement of the trochar and toprevent the telescopically engaged elements from becoming disengaged.

FIG. 11 shows how a modified lock arrangement could be mounted on eachfinger piece 22 to lock the trochar in adjusted position. The lockarrangement comprises a nut 48 threaded to tubular element 50 so thatthe nut can be tightened up to clamp the respective finger piece 22fixedly to guide ring 16 in any adjusted position of the finger piece.

In FIG. 7, a stainless steel tube is flattened out and formed to anarcuate shape to form a double walled tubular member as indicated at 60with'the ends thereof telescopically engaged between a pair of parallelarcuate sheets 62 and 64. Finger pieces 66 on the ends of the element 60are disposed in slots in sheet 64 and can be employed for adjusting thediameter of the trochar. In this modification, a spring 68 may bedisposed between sheets 62 and 64 and engages the ends of element 60when the diameter of the trochar is reduced and urges the said endsoutwardly. The spring 68 may be omitted if desired and the finger pieces66 can be utilized to expand the trochar.

FIG. 8 shows a modification similar to that first described except threefolded sheet elements 70, 72 and 74 are arranged in telescopicengagement. The diameter of the trochar of FIG. 8 can be adjusted in thesame manner as in respect of the first described modification, exceptthat the FIG. 8 modification has three adjustable finger pieces 76, 78and 80.

FIG. 9 shows a modification in which there is mounted within guide ring82, an outer tubular element 84 split down one side at 85 while insideelement 84 is an inner tubular element 86 split down the opposite sideat 87. The free ends of inner element 86 are provided with finger pieces88 extending radially through circumferential slots provided therefor inouter element 84 and guide ring 82 to permit expansion-and contractionof the trochar.

FIG. 10 shows a modification in which a single strip 90 of stainlesssteel is wound up in a spiral to form a tube with finger pieces 92connected to the inner and of the spiral and extending radiallyoutwardly through a slot formed in the other convolutions of thespirally wound sheet. A post 93 is provided and serves the same purposeas previously described. By adjusting the finger pieces relative to theouter end of the wound up sheet, the diameter of the trochar can beadjusted.

Finally, FIG. 12 shows a modification in which a blunt shaped guidingportion 96 having an obliqued or curved blunt tip portion 97 is providedfor substitution of the sharp tipped piercing instrument 14. The trocharwith the curved tip guiding portion 96 is used as a uterine or urethraldilator. After placement of the trochar in the desired position the tubecan be expanded in the same manner as previously described.

All of the trochars described are tubular for receiving a puncturing orguiding instrument, and all are adjustable as to diameter, and all canbe provided with locking means to lock the trochar in adjustedpositions.

The invention has been described with reference to particularmodifications but it will be understood that modifications may be madewithin the purview of the appended claims.

What is claimed is:

1. A trochar comprising an elongated tubular portion open at both endshaving slidable received therein a removable piercing instrument havinga body piercing point protruding from one end of said tubular portion,said tubular portion being formed of at least two thin expandable sheetelements concave toward the axis of said tubular portion and having thecircumferential terminal regions in overlapping relation to define saidtubular portion, and adjustable means disposed at the other end of thetubular portion including means connected to said concave elements forradially expanding and retracting the sheet elements to increase ordecrease the diameter of the tubular portion substantially throughoutthe longitudinal length of the elongated tubular portion.

2. A trochar according to claim 1 wherein the piercing instrument isprovided with a curved blunt tip portion protruding from one end of thetubular portion.

3. A trochar according to claim 1 in which one end of said tubularportion is adapted for insertion into the body, and a guide ring at theother end of said tubular portion supporting said sheet means and saidadjustable means.

4. A trochar according to claim 3 in which said adjustable meansincludes at least one finger piece connected to said sheet elements andprojecting radially outwardly therefrom, and circumferential slotelements formed in said guide ring and moveably receiving said fingerpiece means.

5. A trochar according to claim 3 in which said sheet means comprises atleast two elements each of which is in the form of a sheet of metaldoubled back on itself so as to have one end closed and the other open,each element having a smaller radial thickness extending from the closedend about half the circumferential length of the element and theremainder of the circumferential length of the element having a largerradial thickness, each element being concave toward the axis of thetrochar and the closed end of each element telescopically engaging theopen end of the element next adjacent thereto.

6. A trochar according to claim 5 in which stop tabs are provided on theopposite ends of said elements which interengage with-the stop tabs atthe next adjacent element in the position of minimum telescopicengagement of said elements to prevent said elements from becomingdisengaged from each other.

7. A trochar according-to claim 5 which includes a post fixed to theradially outer side near the open end of each element and projectingradially therefrom, an aperture in said guide ring for each post, afinger piece connected to each element near the closed end thereof andprojecting radially therefrom, and slots formed in said guide ring andin the radially outer part of the radially trochar part of each elementthrough which said finger pieces extend and along which said fingerpieces are moveable.

8. A trochar according to claim 3 in which said sheet elements comprisesa first sheet element concave toward the axis of said trochar, andsecond and third sheet elements concave toward the said of said trocharand in radially spaced relation and receiving therebetween thecircumferential ends of said first sheet element.

9. A trochar according to claim 8 which includes a compression springbetween said second and third sheet elements adapted to engage thecircumferential ends of said first sheet element.

10. A trochar according to claim 8 in which said first sheet elementcomprises a double walled tubular memher which is thin in the radialdirection of said trochar.

11. A trochar according to claim 3 in which said trochar includes flangemeans at the guide ring end thereof.

12. A trochar according to claim 11 in which said flanges are connectedto the axially outwardly facing end of said guide ring.

13. A trochar according to claim 1 which includes means for locking saidadjustable means in adjusted position thereof.

14. A trochar according to claim 1 in which said sheet means is formedof corrosion resistant metal- 15. A trochar according to claim 14 inwhich said metal is stainless steel.

16. A trochar according to claim 3 which includes retaining meansretaining the overlapping regions of said sheet means in close face toface sliding engagement.

17. A trochar according to claim 16 in which each said retaining meanscomprises an element secured to the radially inner one of said sheetmeans and projecting outwardly therefrom and then axially along theoutside of the radially outer one of said sheet means and slidablyengaging the outside of said radially outer one of said sheet means.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent $789,852Dated Februarv 5. 197A lnventofls) Sung Soo Kim and Andress Dusseau Itis certified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

Col. 5, line 33, (Claim 3) "means" should be elements Col. 5, vline 38,(Claim 4) "elements" should be means Signed and sealed this L .th day ofJune 1971;. f,

(SEAL) Attest:

EDWARD M.FLETCHER,JR. Attesting Officer C. MARSHALL DANN Commissioner ofPatents

1. A trochar comprising an elongated tubular portion open at both endshaving slidable received therein a removable piercing instrument havinga body piercing point protruding from one end of said tubular portion,said tubular portion being formed of at least two thin expandable sheetelements concave toward the axis of said tubular portion and having thecircumferential terminal regions in overlapping relation to define saidtubular portion, and adjustable means disposed at the other end of thetubular portion including means connected to said concave elements forradially expanding and retracting the sheet elements to increase ordecrease the diameter of the tubular portion substantially throughoutthe longitudinal length of the elongated tubular portion.
 2. A trocharaccording to claim 1 wherein the piercing instrument is provided with acurved blunt tip portion protruding from one end of the tubular portion.3. A trochar according to claim 1 in which one end of said tubularportion is adapted for insertion into the body, and a guide ring at theother end of said tubular portion supporting said sheet means and saidadjustable means.
 4. A trochar according to claim 3 in which saidadjustable means includes at least one finger piece connected to saidsheet elements and projecting radially outwardly therefrom, andcircumferential slot elements formed in said guide ring and moveablyreceiving said finger piece means.
 5. A trochar according to claim 3 inwhich said sheet means comprises at least two elements each of which isin the form of a sheet of metal doubled bAck on itself so as to have oneend closed and the other open, each element having a smaller radialthickness extending from the closed end about half the circumferentiallength of the element and the remainder of the circumferential length ofthe element having a larger radial thickness, each element being concavetoward the axis of the trochar and the closed end of each elementtelescopically engaging the open end of the element next adjacentthereto.
 6. A trochar according to claim 5 in which stop tabs areprovided on the opposite ends of said elements which interengage withthe stop tabs at the next adjacent element in the position of minimumtelescopic engagement of said elements to prevent said elements frombecoming disengaged from each other.
 7. A trochar according to claim 5which includes a post fixed to the radially outer side near the open endof each element and projecting radially therefrom, an aperture in saidguide ring for each post, a finger piece connected to each element nearthe closed end thereof and projecting radially therefrom, and slotsformed in said guide ring and in the radially outer part of the radiallytrochar part of each element through which said finger pieces extend andalong which said finger pieces are moveable.
 8. A trochar according toclaim 3 in which said sheet elements comprises a first sheet elementconcave toward the axis of said trochar, and second and third sheetelements concave toward the said of said trochar and in radially spacedrelation and receiving therebetween the circumferential ends of saidfirst sheet element.
 9. A trochar according to claim 8 which includes acompression spring between said second and third sheet elements adaptedto engage the circumferential ends of said first sheet element.
 10. Atrochar according to claim 8 in which said first sheet element comprisesa double walled tubular member which is thin in the radial direction ofsaid trochar.
 11. A trochar according to claim 3 in which said trocharincludes flange means at the guide ring end thereof.
 12. A trocharaccording to claim 11 in which said flanges are connected to the axiallyoutwardly facing end of said guide ring.
 13. A trochar according toclaim 1 which includes means for locking said adjustable means inadjusted position thereof.
 14. A trochar according to claim 1 in whichsaid sheet means is formed of corrosion resistant metal.
 15. A trocharaccording to claim 14 in which said metal is stainless steel.
 16. Atrochar according to claim 3 which includes retaining means retainingthe overlapping regions of said sheet means in close face to facesliding engagement.
 17. A trochar according to claim 16 in which eachsaid retaining means comprises an element secured to the radially innerone of said sheet means and projecting outwardly therefrom and thenaxially along the outside of the radially outer one of said sheet meansand slidably engaging the outside of said radially outer one of saidsheet means.